Replace push_back(Constructor(foo)) with emplace_back(foo) for non-trivial types

If the type isn't trivially moveable emplace can skip a potentially
expensive move. It also saves a couple of characters.


Call sites were found with the ASTMatcher + some semi-automated cleanup.

memberCallExpr(
    argumentCountIs(1), callee(methodDecl(hasName("push_back"))),
    on(hasType(recordDecl(has(namedDecl(hasName("emplace_back")))))),
    hasArgument(0, bindTemporaryExpr(
                       hasType(recordDecl(hasNonTrivialDestructor())),
                       has(constructExpr()))),
    unless(isInTemplateInstantiation()))

No functional change intended.

llvm-svn: 238601

1 files changed, 2 insertions, 3 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 9e017273cb2..aef3905b328 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -946,12 +946,11 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
   if (const FileEntry *ModuleMapFile =
           ModMap.getContainingModuleMapFile(Module)) {
     // Use the module map where this module resides.
-    FrontendOpts.Inputs.push_back(
-        FrontendInputFile(ModuleMapFile->getName(), IK));
+    FrontendOpts.Inputs.emplace_back(ModuleMapFile->getName(), IK);
   } else {
     SmallString<128> FakeModuleMapFile(Module->Directory->getName());
     llvm::sys::path::append(FakeModuleMapFile, "__inferred_module.map");
-    FrontendOpts.Inputs.push_back(FrontendInputFile(FakeModuleMapFile, IK));
+    FrontendOpts.Inputs.emplace_back(FakeModuleMapFile, IK);
 
     llvm::raw_string_ostream OS(InferredModuleMapContent);
     Module->print(OS);